Solid Wastes

To understand solid waste, imagine everything we throw away—from kitchen leftovers to demolished concrete. If it is solid and discarded, it becomes solid waste.

What Are Solid Wastes?

Solid waste includes:
→ Garbage
→ Construction debris
→ Sludge from treatment plants
→ Other discarded materials

They originate from:
→ Industries
→ Commercial establishments
→ Mining activities
→ Agriculture
→ Households

A major category is Municipal Solid Waste (MSW), which includes everyday items:
paper, plastics, food waste, metals, glass, rubber, textiles, leather, etc.

Sources of Solid Wastes

To understand management, we must understand where waste comes from.

A. Industrial Solid Wastes

Large industries generate huge quantities, but many by-products can actually be reused.

1. Thermal Power Plants → Fly Ash

• Fly ash improves concrete quality and increases road life.

2. Iron & Steel Plants → Blast Furnace Slag

Used in:
→ Portland cement
→ Road and railway construction
→ Soil conditioning

3. Aluminium, Copper, Zinc Industries → Red Mud

Can be used in:
→ Bricks
→ Roofing tiles
→ Lightweight aggregates

4. Sugar Industries → Press Mud

Used as:
→ Soil conditioner
→ Organic fertiliser

5. Pulp & Paper Industry → Lime Mud

Used in:
→ Bricks
→ Cement
→ Wastewater treatment
→ Agriculture

6. Fertiliser Industry → Gypsum

Used to:
→ Treat alkaline soils
→ Make Portland cement
→ Manufacture Plaster of Paris

B. Residential and Commercial Waste

Includes:
→ Food waste
→ Plastics, paper, glass
→ Leather, textiles
→ Tyres, batteries, electronics
→ Wood, cardboard, used oil

This is the most visible form of waste in cities.

C. Construction and Demolition (C&D) Waste

Comes from:
→ New construction
→ Road repair
→ Building renovation
→ Demolition

Typical materials: Steel, Concrete, Wood, Plastics, Rubber, Copper wires, Glass, Soil and debris

D. Bio-Medical Waste

Generated by: Hospitals, Clinics, Laboratories and Biomedical equipment industries

Includes: Syringes, Bandages, Gloves, Plastics, Chemicals and Drugs

Handling this waste incorrectly can cause infection and toxic exposure.

Solid Waste Management

Defined as:

• Collecting
• Segregating    
• Treating
• Disposing
• Promoting recycling

Under the 12th Schedule of the 74th Constitutional Amendment (1992), urban local bodies (ULBs) are responsible for keeping cities clean.

But most ULBs face:

• Poor institutional capacity
• Lack of funds
• Inadequate infrastructure
• Weak political commitment

Methods of Waste Disposal

A. Open Dumps

Characteristics:
→ Waste is thrown in open, uncovered areas
→ No segregation
→ No treatment

Problems:
→ Breeding ground for rodents, flies
→ Stinking environment
→ Rainwater runoff contaminates land and water

B. Landfills

A landfill is:
→ A pit dug in the ground
→ Waste dumped and covered daily with soil

After filling, the area can be converted into: Parks and Parking lots

Issue: Leaching

When rainwater passes through waste, it contaminates soil and Groundwater

Garbage generation has increased so much that landfills have become huge mountains (e.g., Ghazipur Landfill, Delhi).

C. Sanitary Landfills

Developed to overcome problems of open dumping and traditional landfills.

Features:

• Built systematically
• Lined with impermeable materials (plastic, clay)
• Prevent leaching
• More hygienic

Limitation: Very expensive to build and maintain.

D. Incineration Plants

Process:

• Waste is burned at high temperatures
• Recyclables are removed beforehand

But:

• Produces toxic ash
• Pollutes air
• Used mainly for infectious biomedical waste

Incineration is considered a last resort.

E. Pyrolysis

A more controlled method than incineration.

Definition:

• Burning organic material in absence of oxygen or under very controlled oxygen.

Products:

• Charcoal
• Tar
• Methyl alcohol
• Acetic acid
• Fuel gas

Materials suitable: Firewood, Coconut/palm waste, Corn cobs, Cashew shells, Rice husk, Paddy straw, Sawdust

F. Plasma Gasification

A very advanced technology.

Process:

• Uses extreme heat and electricity to create plasma
• Converts organic matter → syngas (hydrogen + carbon monoxide)
• Converts inorganic waste → slag

Advantages:

• Cleaner than landfills
• Minimizes toxicity
• Reduces volume of waste drastically

Composting

A natural, biological process.

Microorganisms decompose organic waste (food scraps, leaves) in presence of oxygen, turning them into humus-like compost.

Benefits:

• Rich in carbon & nitrogen
• Improves soil structure
• Increases water retention
• Enhances plant growth

Vermiculture

This is composting with earthworms.

Earthworms:

• Break down waste quickly
• Release nutrient-rich castings
  Result: High-quality organic fertiliser

Biomining for Recycling

Biomining uses Bacteria, Fungi, Plants to extract metals from Ores and Solid wastes

Organisms release enzymes/acids → bioleaching metals such as:
→ Copper
→ Nickel
→ Uranium
→ Gold

This reduces the need for destructive mining practices.

Waste-to-Energy (WTE) Plants

Goal:

• Convert waste → electricity or heat

Process:

1. Segregation of wet and dry waste
2. Wet waste → composting or biomethanation
3. Dry waste → WTE plants

Here, dry waste is converted into Refuse Derived Fuel (RDF) with calorific value 2,500 kJ/kg.

RDF is a renewable fuel and reduces landfill burden.

Challenges with WTE Plants

1. High Operational Cost

India depends heavily on foreign technology.

2. Nature of Indian Waste

Indian Municipal Solid Waste contains:
→ High moisture (15–20%)
→ High inert content

WTE plants require:
→ <5% moisture
→ <5% inert material

3. Poor Segregation

Segregation at source is rare → increases treatment cost.

4. Low Calorific Value

Soil/silt reduces fuel quality.

5. High Power Tariff

Electricity from WTE costs ₹7–8/kWh, compared to ₹3–4/kWh from coal.
This makes WTE less attractive to power companies.

Measures to Manage Solid Waste

When we talk of solid waste management, we are essentially answering one question:
How do we prevent the waste we generate from harming society and the environment?
India’s response is structured mainly around the Solid Waste Management Rules, 2016, along with specialised rules for Biomedical Waste.

Solid Waste Management Rules (2016)

These rules replaced the older Municipal Solid Waste Rules, 2000.

The biggest improvement is expansion of coverage—now applicable not only to municipal areas but also to:
→ Urban agglomerations
→ Notified industrial townships
→ Indian Railways properties
→ Airports
→ Defence establishments
→ Pilgrimage centres and religious places

Essentially, any place generating solid waste falls under these rules.

Responsibilities of Waste Generators

For the first time, citizens and institutions are mandated to segregate waste into three streams before handing it over:

1. Wet waste (biodegradable)
2. Dry waste (plastic, paper, metal, wood, etc.)
3. Domestic hazardous waste
   (diapers, sanitary waste, mosquito repellents, cleaning agent containers, etc.)

This segregation is crucial because segregated waste = recoverable waste.

Segregation at Source — A Major Reform

The rules strongly emphasise “waste to wealth”.

Key mandates:

• Gatherings of 100+ persons must segregate waste on-site.
• Hotels and restaurants must:
  • Segregate biodegradable waste
  • Set up systems for composting/biomethanation
• Resident Welfare Associations (RWAs), market associations, gated communities above 5,000 sq m must:
  • Segregate waste
  • Hand over recyclable material to authorised recyclers

This shifts responsibility from the municipality to citizen-level action.

Collect-Back Scheme for Packaging Waste

Brand owners using non-biodegradable packaging must:
→ Create a system to collect back packaging waste

This is a part of Extended Producer Responsibility (EPR).

User Fees for Waste Collection

Municipalities are empowered to:

• Charge a User Fee for collection & disposal
• Impose Spot Fines for:
  • Littering
  • Not segregating waste at source

This introduces a financial discipline in waste management.

Waste Processing & Treatment Mandates

For biodegradable waste:

• Must be processed via composting or biomethanation

For old dump sites:

• Rules mandate bioremediation or capping of legacy waste dumps within 5 years.

For local bodies:

• Must set up waste-processing facilities within a specified timeline.

Promotion of Waste-to-Energy (WTE)

Industrial units located within 100 km of an RDF (Refuse Derived Fuel) plant must use at least 5% RDF in their fuel mix.

The Ministry of New and Renewable Energy (MNRE) must support WTE infrastructure with subsidies and incentives.

This is to reduce dependence on landfills.

Revised Environmental Parameters

Landfill site criteria:

• 100 m from a river
• 200 m from a pond
• 500 m from highways, habitations, parks, water supply wells
• 20 km from airports

Emission standards:

• Revised for dioxins, furans, particulate matter, etc.

Compost standards:

• Brought in line with the Fertilizer Control Order (FCO).

Promoting the Use of Compost

Two ministries are given explicit responsibilities:

Ministry of Chemicals & Fertilizers

• Provide market development assistance for city compost

Ministry of Agriculture

• Offer flexibility within FCO
• Promote use of compost on agricultural land

This enhances soil health and reduces chemical fertiliser dependence.

Central Monitoring Committee

A Committee chaired by the Secretary, MoEFCC will:
→ Monitor implementation of SWM Rules
→ Coordinate between ministries and states

This ensures oversight at the national level.

Additional Important Provisions

• Integration of rag pickers into the formal sector
• Zero tolerance for throwing or burning solid waste in public spaces
• Manufacturers of sanitary napkins must create awareness about proper disposal
• In hilly areas, landfill sites should be located within 25 km

Solid Waste Management Rules 2024 (Draft)

• Segregation: Mandatory; fines for non-compliance; “Polluter Pays” principle.
• Institutions: Complexes >5,000 sq. m must segregate, recycle, compost, hand over residual waste.
• Circular Economy: Waste-to-energy, product manufacturing from waste.
• Penalties: Environmental compensation for violations.
• Agriculture: Gram panchayats to prevent open burning; heavy fines for violators.

Bio-Medical Waste Management Rules, 2016

An upgrade over the 1998 rules.

Bio-medical waste includes:
→ Human/animal tissues
→ Blood-soiled materials
→ Syringes, needles
→ Laboratory waste
→ Material generated at hospitals, clinics, labs, immunisation centres

Salient Features

1. Phase-out of chlorinated plastics

Within two years, remove:
→ Chlorinated bags
→ Gloves
→ Blood bags

2. Pre-treatment

Laboratory and microbiological waste must be sterilised on-site.

3. Barcoding

All biomedical waste bags/containers must carry barcodes.

4. 4 Categories Instead of 10

Reduces confusion and improves segregation.

5. State Governments’ Role

• Provide land for common biomedical waste treatment facilities (CBWTFs).

6. “75 km Rule”

If a CBWTF is available within 75 km, hospitals cannot set up their own treatment facility.

7. Operator responsibilities

Operators must ensure timely collection from healthcare facilities.

8. Camps Included

Vaccination camps, blood donation camps etc., are also covered.

Procedure for Hospitals

Hospitals must:

• Segregate biomedical waste in prescribed categories
• Obtain authorisation if treating 1,000+ patients/month
• Example:
  • Syringes, blood-soaked bandages → Red bag → Incineration

If body fluids are present → mandatory incineration.

Problems Due to Unscientific Disposal

• 85% of hospital waste is non-hazardous, 15% is infectious
• Mixing both makes the entire batch hazardous
• Leads to:
  • Reuse of prohibited items (syringes/drugs)
  • Spread of infection
  • Development of antimicrobial resistance (AMR)

Waste Minimization Circles (WMC)

Objectives:

• Help small and medium industries reduce waste
• Implemented by:
  • World Bank
  • National Productivity Council
  • MoEFCC (nodal ministry)

Linked to the Policy Statement for Abatement of Pollution (1992), which emphasises:
→ Public awareness
→ Involvement of citizens & NGOs in environmental monitoring